1. Technical Field
The present invention relates generally to balloon catheters, and more particularly, to a balloon catheter assembly for use in angioplasty procedures wherein the balloon portion of the assembly is provided with plaque-cutting edges disposed along the outer surface of the balloon.
2. Background Information
Coronary artery disease, or atherosclerosis, results in restrictions in the flow of blood to the heart and other areas of the circulatory system. Such restrictions occur primarily as a result of the formation of obstructions, such as plaque, in one or more of the blood vessels of the patient.
The medical community has long sought effective ways to remove such obstructions to restore the free blood flow in the vessel, and to maintain that flow for an extended period of time. One technique that has come into widespread use for treating atherosclerosis is known as percutaneous transluminal coronary angioplasty (PTCA), or as it is more commonly known, balloon angioplasty. Balloon angioplasty is utilized to open arteries whose lumens have been restricted due to this build-up of plaque, a condition known as stenosis. In a typical balloon angioplasty procedure, an incision is made in a specific area of the patient's body to gain access to an artery, such as the femoral artery. A balloon-tipped catheter is inserted into the artery and threaded through the artery to the site of the blockage. When the blockage site is reached, the balloon is inflated. The inflated balloon pushes the plaque back against the artery wall, thereby removing the restriction and restoring the pathway for blood flow through the vessel. The balloon may be deflated and re-inflated one or more additional times. If desired, a stent may be inserted at the position of the blockage to prop the artery open.
Balloon angioplasty has been well-received in the medical field as an alternative for the much more invasive and expensive surgical by-pass techniques. Although balloon angioplasty and related procedures have proven successful in many cases for treating coronary artery disease, the procedure continues to suffer from some shortcomings. Since the plaque is pressed against the vessel wall, it is not generally removed from the vessel. In a significant number of patients, the plaque re-forms as a restriction and re-clogs the artery, a condition referred to as restenosis. When restenosis occurs, it is often necessary to repeat the balloon angioplasty procedure, or in some instances, undertake a more invasive procedure, such as cardiac by-pass surgery.
In addition, in some severe cases of stenosis, the plaque deposit may have hardened or become calcified to such an extent that it does not easily yield to the balloon. In such instances, balloon angioplasty must often be carried out at higher pressures to crack the calcified plaque. When higher pressures are employed, the physician must exercise a high amount of care to avoid rupturing the balloon and/or the artery at the site of the plaque deposit.
It is desired to provide a balloon angioplasty device that is capable of breaking down build-ups of plaque from a vessel, and that is capable of cracking calcified plaque at low pressures such that the inherent risks of rupture of the balloon and/or artery may be minimized.